The present invention relates to tubular devices which can be force fitted into a bore and, in particular, to devices which are used to either stabilize underground strata or to fasten.
It is known to provide a fastener in the form of a spring pin which is a generally compressible sleeve that can be force fitted into a hole. In addition, it is known to employ a sleeve having an elliptical cross-section which is mounted in a hole and expanded by driving a pin into the sleeve. However, this latter sleeve is relatively small and is dimensioned primarily for use as a wall fastener. Thus it does not have sufficient length to stabilize it in unconsolidated rock strata. Furthermore, such sleeves do not have a smooth convex perimeter. Instead they are formed of sheet metal with an overlapping seam. Finally, in the mining art it is known to employ a split cylindrical sleeve which is force fitted into a bore drilled into underground strata.